Question: which series ordinal of osmium tetroxide has ionization energy of 12.6?
Paraphrase: The ionization energy of 12.6 belongs to which series ordinal of osmium tetroxide?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q422021 p:P2260 ?s . ?s ps:P2260 ?x filter(contains(?x , '12.6')) . ?s pq:P1545 ?value}